WO2001075835A1

WO2001075835A1 - Alarm monitoring arrangement

Info

Publication number: WO2001075835A1
Application number: PCT/GB2001/000992
Authority: WO
Inventors: Stephen Michael Reeder
Original assignee: British Telecommunications Public Limited Company
Priority date: 2000-03-31
Filing date: 2001-03-07
Publication date: 2001-10-11
Also published as: GB2376121B; AU2001237589A1; GB0221943D0; GB2376121A

Abstract

In an alarm monitoring arrangement, notification of an alert condition from a detector is deferred for a period of time determined in dependence on any history of false alerts from the detector. Thus in an environment having multiple detectors, any detector giving transmitting an alert and then clearing the alert prior to expiry of the allocated time period has its 'time to respond' period increased in respect of subsequent activation. Periodically the time periods in respect of each detector may be reduced so that normally non-alerting detectors attain a shorter respond period than poorly positioned detectors which create most false alerts. The time period prior to response may be bounded by pre-determined maximum and minimum response periods.

Description

ALARM MONITORING ARRANGEMENT

The present invention relates to an alarm monitoring arrangement and in particular to such an arrangement including local and remote control centres. In published European patent application number 675626 and further in published European patent application number 960407, there is disclosed a security system which utilises the public switched telephone network (PSTN) calling line identity (CLI) to provide theft protection to electrically operable apparatus. Further enhancements of the system are disclosed in co-pending (unpublished) applications numbers EP993021 32.8, EP993021 33.6, EP993021 34.4, EP99302149.2 and EP99307981 .3.

In particular, our co-pending application number EP99307981 .3 discloses an enhancement of the earlier system for use in respect of signals indicative of environmental alarm conditions. The term environmental alarm condition as used is inclusive but not limited to smoke, fire and gas detection alarms, burglar alarms, health monitoring alarms and consumer operable alarms ("panic buttons").

One of the major problems with any kind of alarm system is the potential for false alarms to create an excess of network traffic and potential overload of emergency control centres. While it is essential that genuine environmental alarms are handled in an efficient and effective manner and, in particular, are not overruled merely on the basis of past false alarm activity, overloading an emergency control centre with false alarms, even if subsequently cancelled, may cause a delay in genuine alarms being handled.

According to the present invention there is provided a communications system for handling environmental alarms, said system comprising a communications interface connected to effect communications with a remote operations centre, control means responsive to environmental alarm signals and data storage storing respective data for each of a plurality of environmental detectors, each of said plurality of environment detectors including means for storing a respective identity, control means and detection means for detecting presence of an adverse environmental condition, the control means of each detector responding to an alert condition from the associated detector means to cause transmission of signals including at least a part of said respective identity to the communications interface, said control means further responding to a change in the alert condition indicative of absence of said environmental condition to cause notification of such a change to said communications interface; the control means of said communication interface responding to receipt of an alert condition to cause commencement of a time period determined from respective timer data for the alerting environmental detector and, on expiry of such time period, to cause a communication with the remote operations centre, said control means being further responsive to removal of an alert condition before expiry of said time period to cause modification of the timer data in respect of the alerting environmental detector such that the time period in respect of a subsequent activation of said detector is incremented.

Incrementing of said timer data may be deferred for a predetermined period of time such that the time out period is not increased if a subsequent adverse environmental condition occurs during that predetermined period.

The incrementing of said time period may be inhibited if the time period reaches a predetermined maximum.

The control means of the communications interface may, at predetermined times, decrement the timer data in respect of all of the plurality of environmental detectors controlled thereby. Decrementing may be inhibited if such a decrement would result in the time period being less than a predetermined minimum threshold. A communications system in accordance with the invention will now be described, by way of example only, with reference to the accompanying drawings of which:

Figure 1 is an overview of the system disclosed in published European patent applications number 675626 and 960407;

Figures 2 and 3 are block schematic diagrams showing environmental alarm condition detectors together with a communications interface in, respectively, a home and a community arrangement;

Figure 4 shows a typical detector of the kind fitted in Figures 2 and 3;

Figure 5 is a schematic diagram of the data storage requirement in the detector of Figure 4; Figure 6 shows typical data storage arrangements in the remote operations centre of Figure 1 ;

Figure 7 shows volatile data storage in the interface of Figure 2;

Figure 8 shows non-volatile data storage in the same interface; Figure 9 to 1 3 show signal interactions between environmental detectors, the control interface at the remote operations centre;

Figure 14 is a block schematic diagram showing the communications interface of Figure 2 in greater detail; and Figure 1 5 shows a part of the software of the control means of Figure 14.

Referring first to Figure 1 , the communications system shown includes typically the PSTN generally indicated at 1 , a typical home environment 3 and a remote operations centre (ROC) 4. Also shown is an emergency control centre 8. The first use of such a system was intended to provide electrical appliances (typically shown at 5) with a module responsive to signalling received to store an identity code. By requiring input of the identity code on each occasion at which the electrical appliance 5 was connected to a mains electricity supply e.g. 6, disconnection of the electrical appliance 5 for the purposes of theft would render the apparatus of no value. In essence then, a home control centre (HCC) 2 monitored the main electricity supply 6 for signalling from the electrical appliance 5 indicative of reconnection or first connection to the electricity supply. On first connection the HCC 2 would communicate by way of the communications line 7 with the ROC 4 to notify that centre of the presence of the appliance and to request codes for that appliance. The ROC 4 processor would provide unique identity and blanking codes for the electrical appliance 5 and would store information relating to the appliance in respect of the CLI of the telephone line 7. The HCC 2 stores the identity in respect of the electrical appliance so that each time the appliance is reconnected the HCC 2 will transmit to the mains the unique identity code in response to a request. This enables the electrical appliance to cease to operate in the absence of the required coding within a predetermined period of time.

Referring additionally now to Figure 2, in a further development of the system, a detector 1 1 and an alarm switch 1 2 also communicating by way of the mains electricity supply 6, for example, were provided. Once registered to the HCC 2, any environmental alert arising from either the detector 1 1 or the alarm switch 1 2 would result in the HCC 2 placing a call by way of the PSTN to the emergency control centre 8 of Figure 1 , the CLI of the communications line 7 being transmitted to the screen 9 of the emergency control centre 8, whereby the location of the alert could be determined. Figure 3 shows a further development of the system of Figure 2 for use purely in a community environment where the communications interface 21 monitors the mains electricity supply 6 of, for example, and apartment or tenement building.

A number of detectors 1 1 are distributed throughout the building each having its own unique identity. In all other respects the community control centre operates in the same manner as the HCC 2 in responding to the presence of a detected environmental alarm condition by transmitting a telephone call to the PSTN and thence to the emergency control centre, together with the identity of the alerting detector or detectors. Thus, turning to Figure 4, each of the detectors 1 1 typically comprises sensor circuits 14 which are interactive with a process controller 1 5, (for example a microprocessor) responsive to activation of the sensor circuit to cause transfer of data identifying the detector unit 1 1 held in the data store 1 6.

This information is superimposed on the mains electricity supply line 6 by a signal generator 1 8 under control of the processor control unit 1 5. Note also the presence of a signal interface 1 7 arranged to allow communication in the opposed direction, that is from the electricity supply line 6 to the processor control 1 5 whereby test responses and registration arrangements with a HCC 2 or community control centre 21 might be effected. Figure 5 shows the data storage information required in the data store 1 6, this being a minimum of a manufacturer reference, manufacturer's equipment reference and an electronic serial number.

Figure 6 shows data storage at the ROC 4 of Figure 1 . The data storage at the ROC 4 is on a customer location basis, including a location code of 40 bits, a general unlock code and the identity of the customer together with personal identification numbers to allow blanking of pre-secured apparatus. The customer's name and address may also be stored, such that in an alert condition it will be possible for the ROC in communication with the emergency control centre 8 to assist identity of the location of an alerting device. In respect of each customer location or HCC 2 the ROC 4 stores a listing for each appliance including its electronic serial number, an individual unlocking code and a blanking code. Further details of the operation of the ROC 4 and of the HCC 2 in respect of protected apparatus may be found by reference to the previously referenced patent applications and are not further discussed herein.

Note that from Figure 7 the data storage of the HCC 2 reflects the appliance data held at the ROC 4, this being held in a volatile data store so that if the HCC 2 is disconnected from the mains unit it cannot be used in conjunction with the other apparatus in another location except by a prior arrangement with a predetermined CLI. Power disconnection from the HCC 2 and subsequent reconnection will result in the HCC 2 communicating with the ROC 4 to obtain the appropriate release codes for the appliances 5 present. In respect of alarm units, the HCC 2 and/or community control centre 21 may have a non-volatile storage arrangement. In this arrangement the number of alarms in the list may be stored and on a per alarm basis the manufacturers reference, manufacturer's equipment reference and electronic serial number, as indicated in Figure 5, will be stored. In association with the alarms data for each alarm detector is a response time data byte. As hereinafter described, the response time information determines the length of time for which an alarm condition must be present before the ROC 4 is contacted.

Referring now to Figure 9, before any apparatus is used in a protected environment, it is necessary for it to be registered. For this reason the HCC 2 or the community control centre 21 , as appropriate, includes a registration button to which the control means of the communications interface is responsive to commence an equipment register timer. Each of the detectors has a corresponding register button so that, provided the register button is pressed within a period commenced when the control centre button is depressed, a registration request is sent by way of the mains electricity supply 6 (as shown in the present case) or by radio communication or such other method as by Intra or inter-network communication. When the HCC 2 or communication control centre 21 receives a registration request from a detector or environmental monitor, it forwards a corresponding registration request by way of the PSTN (or Cellnet or inter-network communication) to the ROC 4. The ROC 4 will register the detector and in particular its serial number to the customer's account and will forward a registration response confirming that the apparatus has been registered. On receipt of the registration response, the HCC 2 or the community control centre completes the data storage in respect of the detector and forwards a registration response signal to the environment monitor to cause an audio and/or visual confirmation of the registration of the device.

Referring now to Figure 10, if one of the environmental detectors 1 1 detects an alarm condition it forwards a signal by way of the electricity supply 6 or by other means referenced in co-pending patent applications, to the community control centre 21 or the HCC 2 as appropriate. The control centre, on receipt of an alarm condition, contacts the ROC 4 with an alarm condition alert signal and the ROC 4 commences a false alarm cover timer. At the same time or subsequently the ROC 4 returns an alarm condition response to the control centre 2 or 21 to cause the control centre to forward an acknowledgement signal to the relevant detector. Once the false alarm cover time expires at the ROC 4, then a full alarm condition initiation may occur. This is shown in Figure 1 2 in which on expiry of the false alarm cover time the alarm condition is initiated. A s shown a voice telephone call is sent to the customer (where practical) and if the customer answers and states that the alarm is false then the condition may be cleared. If there is no answer from the customer (or there is no telephony confirmation available) then the third party agent at the emergency control centre 8 may be alerted. For the avoidance of doubt, it is here noted that while the false alarm cover timer may be a function of the ROC 4 it may alternatively be a function of the community control centre 21 or the HCC 2 since timer data is stored in respect of each environmental detector 1 1 present in particular premises.

As shown in Figure 1 1 , if subsequent to the alarm condition response from the ROC 4 and HCC 2 the environmental monitor or detector unit and alarm condition clears a condition clear message from the detector may be transmitted back to the communications control centres and thence to the remote operations centre which will stop the false alarm cover timer thereby not causing alerting of the emergency service. Once the false alarm cover timer stops then a re-alert timer commences so that if the alarm condition recurs prior to expiry of this timer earlier notification of the emergency services may occur. Figure 13 allows for testing of the alarms provided so that if a user selects the test function of an alarm device a signal is generated which is forwarded by way of the mains electrical circuit 6 (or other appropriate signalling method) to the HCC 2 or Community control centre 21 . This results in the control centre forwarding a message to the ROC 4 which returns a test response signal to the alarm unit (by way if the control centre) so that an audible and/or visual indication of the success of the test may be provided.

Turning now to figure 14, the home or community control centre 2,21 typically comprise a processor 23 (for example a micro-processor), in association with a data store 24. Connected to a line 7 to the PSTN by way of an appropriate network termination 20 there is a tone generator and modem for communication with the remote operations centre 4. An analogue shift keying interface is also provided to effect two way communication with a mains electricity supply line 6 and thence to communicating appliances or detectors of the premises.

Figure 1 5 to which reference is now made shows one method of implementing the false alarm prevention arrangement in the home control centre 2 (or Community control centre 21 ). Generally the system remains quiescent in a main state 29 until it receives an input from a connected device or it is triggered by a decaying timer. Thus in respect of theft protected apparatus the processor 1 5 may leave the quiescent state 29 through the unlock request response path 30. The actions of the control centre 2 and ROC 4 in respect of an unlock request are fully flow charted and explained in previous published applications of the proprietor and, since there is no requirement to understand these operations fully to permit understanding of the present invention the path is not further detailed herein.

A register request from a detector provides an input signal by way of the mains electrical supply 6, the signal being received 31 by way of the ASK interface. The signal results in the control centre effecting a call by way of the PSTN to the remote operations centre 4 and transmitting by way of the modem a registration request message 32 including the identity of the registering detector by its manufacturers coding and serial number for example. The remote operations centre responds with a registration response 33 after which the detector is added to the list (34) of detectors at the premises. Finally the HCC2 causes a registration response to be sent by way of the ASK interface to the detector to allow an audible and/or visual response to be given confirming the registration of the detector.

If an alert signal from a detector is received (36) a check is carried out to determine whether the detector is registered (37) and, if not an alarm response timer is set (43) to monitor the electrical supply line for further signals indicating either that the alarm has cleared (not shown) or that the alarm receives an alarm condition response 44. The alarm condition response (if received) indicates that the detector is registered with another control centre 2,21 which is functioning. Thus once the alarm condition response has been detected at step 44 the timer may be cleared and the process revert to the quiescent state.

Returning to step 37, if the detector is present in the list then at step 50 timer data is extracted from the data store in respect of the particular alarm and a countdown commenced (step 51 ). The electricity supply line 6 is monitored for the presence of an alarm condition clear condition 52 and if the condition clears prior to expiry of the timer set the timer data in respect of the particular alarm is checked to see if it is already at a maximum pre determined value (step 53) and if not the timer is incremented so that any subsequent alarm from the same detector must persist for longer before the alarm is raised with the remote operation centre. Once the timer expires at step 51 then a call is made through the PSTN to the remote operations centre and an alarm condition alert is forwarded 38 awaiting an alarm condition response 39 from the ROC such that the local control centre may forward an alarm condition response to the detector unit (40) . The control centre continues to monitor for an early clearance of the alarm condition and if an alarm condition clear is subsequently received (42) may again modify timer data in respect of the alerting detector through the path 53, 54.

Returning now to the preceding drawing, if the decrement timer expires (60) after a preset interval which may be a week for example, the processor 1 5 examines the data for each detector (61 )in turn and, unless a predetermined minimum time threshold has been reached, (62) decrements the timer data (63) so that a subsequent alarm from the respective detector will result in a faster response.

By using the above method, badly positioned detectors, such as those placed adjacent to a kitchen rapidly reach an elongated response time so that a false alarm is less likely to be given whereas detectors which rarely alert are given a more rapid response. It is here noted that if more than one detector alerts then the shorter or shortest timer period is used to determine the time at which the remote centre is contacted.

Claims

1 . A communications system for handling environmental alarms, said system comprising: a communications interface connected to effect communications with a remote operations centre, control means responsive to environmental alarm signals and data storage storing respective data for each of a plurality of environmental detectors, each of said plurality of environment detectors including means for storing a respective identity, control means and detection means for detecting presence of an adverse environmental condition, the control means of each detector responding to an alert condition from the associated detector means to cause transmission of signals including at least a part of said respective identity to the communications interface, said control means further responding to a change in the alert condition indicative of absence of said environmental condition to cause notification of such a change to said communications interface; the control means of said communication interface responding to receipt of an alert condition to cause commencement of a time period determined from respective timer data for the alerting environmental detector and, on expiry of such time period, to cause a communication with the remote operations centre, said control means being further responsive to removal of an alert condition before expiry of said time period to cause modification of the timer data in respect of the alerting environmental detector such that the time period in respect of a subsequent activation of said detector is lengthened.

2. A communications system as claimed in claim 1 in which modification of the timer data is deferred for a pre-determined period after removal of the alert condition whereby communication with the remote operations centre is not adversely affected by a temporary break in persistence of an alert condition.

3. A communications system as claimed in claim 1 or claim 2 in which the control means is arranged to modify timer data in respect of each associated environmental detector on a periodic basis whereby the time period in respect of subsequent activation of each detector is shortened.

4. A communications system as claimed in any preceding claim in which modification of the time period by the control means is inhibited if such modification would cause the time period to exceed a pre-determined maximum period.

5. A communications system as claimed in any preceding claim in which modification of the time period by the control means is inhibited if such modification would cause the time period to be less than a pre-determined minimum period.